Pulsatile blood pumping systems

ABSTRACT

A blood pumping system to support living organisms based on a spherical multi vane and multi chamber pump with an oscillating motion that delivers pulsatile flow. The blood pumping system includes a number of design elements that address the particular needs and compatibility issues (both biological and hemological) of a blood pumping system.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and claims priority of U.S.application Ser. No. 10/824,821 filed Apr. 15, 2004.

TECHNICAL FIELD

The invention relates generally to artificial heart pumping systems thatcan be used either externally (non-implantable) or internally(implantable) with respect to the human body for maintaininglife-sustaining circulation.

BACKGROUND

The failure of the heart to provide adequate circulation of blood is aserious life-threatening problem. Heart transplants have treated themost serious cases of heart failures. A heart transplants though is adrastic procedure with high risk and the supply of donors is limitedwhen compared to the total need. Considerable research and developmenthas been done therefore into developing artificial hearts that canreplace the human heart. Currently most artificial heart blood pumpingsystems are used more as temporary heart assistants pending the locationof a heart donor.

A variety of functional designs for artificial hearts are in the patentprior art and a number of functional designs now exist and are in use atvarious heart centers around the world. The AbioCor™ implantablereplaceable heart, provided by ABIOMED, Inc. is a self-containedimplantable replacement heart. This pump weighs about two pounds andconsists of artificial ventricles that contain corresponding valves anda motor driven hydraulic pumping system. The hydraulic pumping systemuses pressure to move blood from the artificial right ventricle to thelungs or from the artificial left ventricle to the rest of the body. Tocreate this pressure the pump motor rotates at 4000 to 8000 rpm. Anothersystem, the ABIOMED BVS-5000 is an air driven dual chamber blood pumpplaced outside the body used primarily for temporary left, right, orbiventricular support of patients with heart failure. The pump housestwo polyurethane chambers, an atrial chamber that fills with bloodthrough gravitational force and a ventricle chamber that pumps blood byair-driven power. Two trileaflet valves separate the chambers.

The Thoratec HeartMate® implantable pneumatic left ventricular assistsystem is based on an air-driven titanium alloy pump that weighs about570 grams and consists of a blood chamber, an air chamber, a drive lineand inflow and outflow conduits. Each conduit is a titanium cage thatcontains a valve within a Dacron fabric graft. The pump is powered andcontrolled by an external portable console. The Thoratec HeartMate II®is an implantable left ventricular assist system based on a continuousaxial flow in-line pump. There are other artificial blood pumpingsystems under development and in use.

The existing solutions have provided utility and prolonged lives. Thereare still many issues to be addressed however. Many of the priorsolutions provide continuous flow whereas a problem free pulsatile flowthat provides a more physiologic flow of blood is needed. Pulsatile flowis sometimes provided by flexible-volume chambers (bladders, tubing,bellows) but these are susceptible to wear and prone to thrombosis.Thrombosis as related to medical devices is the formation of blood clotson, or inside of, a medical device, and can lead to seriousconsequences. Flexible-volume chambers that do not completely or nearlycompletely expel their contained fluid during each stroke can also beprone to thrombosis. Another issue is simply size. Pumping systems withmultiple chambers and the accompanying drive mechanism are typically toolarge to fit in smaller adults or children. Partially related to size isenergy efficiency, with these systems requiring too much energy tooperate. In addition to size though, many designs are inherently energyinefficient because of mechanisms that require reversing motion(pistons, bladders) that expends additional energy. Another issueevident from the above discussion of some of the existing systems is theuse of valves. Valves not only add to size and complexity (and thereforereliability) but also are prone to calcification, wearing out and tothrombosis. Some of the prior art systems and devices also have problemswith hemolysis (breakdown of red blood cells) due to either mechanicalforces or shear forces in the motion of the fluid. Finally there is adefinite need for easier flow modification of blood pumping systems.Many of the existing systems require separate drive force or shunting toaccomplish this. Additionally, none of the prior art devices are knownto provide two streams with simultaneous discharge pulsation peaks orsimultaneous intake strokes, which simultaneity is physiologicallydesirable.

The above needs can be addressed by applying modifications of newpumping technology to the special problems of blood pumping systems.

Spherical rotary pumping systems have been developed that consist of aspherical housing within which one or more vanes rotate. This is incontrast to those devices that utilize a reciprocating, linearly movingpiston. In the case of the spherical rotary pumps the vanes are rotatedby a shaft to cause the fluid to flow through the device.

U.S. Pat. No. 5,199,864 to Stecklein discloses a rotary fluid pump thatemploys vanes rotating within a spherical housing and includes aninterior carrier ring that guides a particular motion of the vanes sothat they open and close to draw in and either pump or compress fluids,thereby creating a type of pulsatile flow. This patent also describes anembodiment (the “second embodiment”) that uses an exterior carrier ringto guide the reciprocal motion of the vanes. These devices are highlyefficient, and are capable of displacing large quantities of fluidrelative to their size, so that the use of a small pump is possible. Theflow of fluid is typically controlled by the rate at which the rotaryvanes are rotated. By increasing the speed, more fluid is pumped throughthe device, while decreasing the speed decreases the amount of fluidpumped.

U.S. Pat. No. 6,241,493 to Turner discloses a particularly usefulimprovement on this type of spherical fluid machine that is configuredto enable adjustments in both fluid capacity and fluid direction withoutchanging the speed or direction of rotation of the vanes in the deviceby adjusting the orientation of an interior carrier ring. That patent isincorporated by reference into this application.

Fluid machines such as that described in U.S. Pat. No. 6,241,493 andU.S. Pat. No. 5,199,864 are also already ported, meaning that the mannerin which the chambers communicate with the inlet and discharge portsnegates the need for valves. They can be especially long running from amaintenance perspective because there is no direct physical contactbetween either the vanes and the central sphere around which they rotatenor physical contact between the vanes and the exterior housing of themachine. Low leakage between chambers is achieved by maintaining smallclearances that minimize slippage or fluid loss across the clearances.

Further improvements to these types of spherical rotary pumps aredisclosed in U.S. patent application Ser. No. 10/784,709 by the inventorof the instant invention and that application is incorporated herein byreference in its entirety. These improvements included adding stabilityto the design, adding internal cooling, incorporating the ability topump multiple fluids, and adding critical seals. Some of theseimprovements were aimed at the dual use of this type of a pump as afluid pump as well as a compressor and/or motor in industrialapplications. It is important to note that none of the prior artreferences on these spherical rotary pumps recognized their potentialvalue as an artificial heart or as a ventricular assist device nor werethe particular issues inherent in adapting this solution for thoseapplications recognized or dealt with in these references. For example,issues related to biocompatibility, hemocompatibility, hemolysis andthrombosis were not addressed. The crux of the instant invention is therecognition of the need and the adaptation of these devices for thisapplication.

SUMMARY

These and other needs are addressed by the present invention, whichsimultaneously provides a method and apparatus for providing a reliable,adjustable pulsatile blood flow with a very small, efficient sphericalblood pump that can be used as an implantable or external device andthat can be easily configured to pump either one or two fluids. Theinstant invention also includes a number of other embodiments thataddress the particular needs of blood pumping systems that will beconnected to a living organism, including improved biocompatibility,improved hemocompatibility and significantly reduced hemolysis andthrombosis.

For purposes of the description here the solutions will be describedwith respect to a fluid machine similar to the one described in U.S.Pat. No. 6,241,493. Accordingly that prior art fluid machine will bedescribed first in some detail. It should be recognized however that theinstant invention could be potentially applied in any spherical pumpsuch as those described in U.S. Pat. No. 5,199,864 or in U.S. Pat. No.5,147,193.

One aspect of the pulsatile blood pumping system of this invention thenincludes at least a housing having a wall defining a generally sphericalinterior, the housing having at least one intake port opening incommunication with the interior of the housing and at least onedischarge port opening in communication with the interior of thehousing, and further including at least a first shaft mounted forrotation relative to the housing about a primary axis, where at least aportion of the first shaft extends through the housing wall and where atleast one primary vane is disposed within the interior of the housingthat rotates about the primary axis of the first shaft; at least onesecondary vane disposed within the interior of the housing and mountedto the primary vane on a first pivotal axis, the secondary vanepivotally oscillating between alternating relatively open and closedpositions with respect to the primary vane and defining at least achamber within the housing interior having a volume which varies as theprimary vane is rotated about the primary axis; and where the at leastone intake port opening and at least one discharge port opening areconnected to circulate at least one blood fluid through a livingorganism.

The pulsatile blood pumping system of this invention also includes atleast a housing having a wall defining a generally spherical interior,the housing having at least one port opening in communication with theinterior of the housing; a first shaft mounted for rotation relative tothe housing about a primary axis, wherein at least a portion of thefirst shaft extends through the housing wall; at least one primary vanedisposed within the interior of the housing that rotates about theprimary axis of the first shaft; at least one secondary vane disposedwithin the interior of the housing and mounted to the primary vane on afirst pivotal axis, the secondary vane pivotally oscillating betweenalternating relatively open and closed positions with respect to theprimary vane and defining at least a chamber within the housing interiorhaving a volume which varies as the primary vane is rotated about theprimary axis; the secondary vane being pivotally coupled to a carrierring, so that the secondary vane is pivotal about a second pivotal axisperpendicular to the axis of rotation of the carrier ring causing thesecondary vane to reciprocate between relatively open and closedpositions as the secondary vane is rotated about the primary axis by thefirst shaft; the axis of rotation of the carrier ring being oriented atan oblique angle in relation to the primary axis of the first shaft; asecond shaft that extends into the interior of the housing opposite thefirst shaft, the second shaft having a spherical portion about which theprimary vane rotates and wherein the carrier ring is rotatably carriedon the spherical portion of the second shaft; and wherein the at leastone intake port opening and at least one discharge port opening areconnected to circulate at least one blood fluid through a livingorganism.

The pulsatile blood pumping system of this invention also includes ahousing having a wall defining a generally spherical interior, thehousing having at least one intake port opening in communication withthe interior of the housing and at least one discharge port opening incommunication with the interior of the housing, and including at least afirst shaft mounted for rotation relative to the housing about a primaryaxis, wherein at least a portion of the first shaft extends through thehousing wall; at least one primary vane disposed within the interior ofthe housing that rotates about the primary axis of the first shaft; atleast one secondary vane disposed within the interior of the housing andmounted to the primary vane on a first pivotal axis, the secondary vanepivotally oscillating between alternating relatively open and closedpositions with respect to the primary vane and defining at least achamber within the housing interior having a volume which varies as theprimary vane is rotated about the primary axis; wherein the at least oneintake port opening and the at least one discharge port opening areoperated simultaneously to both input and discharge blood fluids.

Another aspect of the instant invention is a method for simultaneouslyinputting and discharging at least one blood fluid through a bloodpumping system in a pulsatile manner comprising the steps of providing ahousing having a wall defining a generally spherical interior, thehousing having at least one intake port opening in communication withthe interior of the housing and at least one discharge port opening incommunication with the interior of the housing through which at leastone blood fluid flows connecting at least one intake port opening and atleast one discharge port opening to enable the circulation of at leastone blood fluid through the living organism, rotating a first shaftmounted for rotation relative to the housing about a primary axis,wherein at least a portion of the first shaft extends through thehousing wall; rotating at least one primary vane disposed within theinterior of the housing that rotates about the primary axis; providingat least one secondary vane disposed within the interior of the housingand mounted to the primary vane on a first pivotal axis; and rotatingthe primary vane about the primary axis with the secondary vanepivotally oscillating between alternating relatively open and closedpositions with respect to the primary vane; the housing, the primaryvane, and the secondary vane defining at least one fluid chamber forcontaining fluid within the housing interior having a volume that variesas the primary vane is rotated about the primary axis.

Another aspect of the instant invention is a method for circulating atleast one blood fluid through a living organism in a pulsatile mannercomprising the steps of: providing a housing having a wall defining agenerally spherical interior, the housing having at least one intakeport opening in communication with the interior of the housing and atleast one discharge port opening in communication with the interior ofthe housing through which at least one blood fluid flows connecting atleast one intake port opening and at least one discharge port opening toenable the circulation of at least one blood fluid through the livingorganism, rotating a first shaft mounted for rotation relative to thehousing about a primary axis, wherein at least a portion of the firstshaft extends through the housing wall; rotating at least one primaryvane disposed within the interior of the housing that rotates about theprimary axis; providing at least one secondary vane disposed within theinterior of the housing and mounted to the primary vane on a firstpivotal axis; and rotating the primary vane about the primary axis withthe secondary vane pivotally oscillating between alternating relativelyopen and closed positions with respect to the primary vane; the housing,the primary vane, and the secondary vane defining at least one fluidchamber for containing fluid within the housing interior having a volumethat varies as the primary vane is rotated about the primary axis.

The instant invention also includes a method for simultaneously flowinga first fluid and a second fluid through the same pulsatile bloodpumping system including at least the steps of: providing a housinghaving a wall defining a generally spherical interior, the housinghaving at least one port opening in communication with the interior ofthe housing through which fluid from a fluid source is allowed to flow;providing a first shaft mounted for rotation relative to the housingabout a primary axis, wherein at least a portion of the first shaftextends through the housing wall; providing at least one primary vanedisposed within the interior of the housing that rotates about theprimary axis; providing at least one secondary vane disposed within theinterior of the housing and mounted to the primary vane on a firstpivotal axis; rotating the primary vane about the primary axis with thesecondary vane pivotally oscillating between alternating relatively openand closed positions with respect to the primary vane, the housing, theprimary vane, and the secondary vane defining a fluid chamber forcontaining fluid within the housing interior having a volume that variesas the primary vane is rotated about the primary axis; and providing afirst fluid and a second fluid and connecting the first and secondfluids to appropriate port openings to enable separate movement of thefirst and second fluids through the pulsatile blood pumping system.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front perspective view of a pulsatile blood pump, shown withthe upper half of a housing of the pump exploded away to reveal internalcomponents of the device;

FIG. 2 is a perspective view of the lower half of the housing of thepump of FIG. 1 with the internal components removed;

FIG. 3 is a perspective view of a input shaft and primary vane assemblyof the pump of FIG. 1, shown with the primary vane assembly explodedinto two halves;

FIG. 4 is a perspective view of a secondary vane assembly of the pump ofFIG. 1, shown with the secondary vane assembly exploded into two halves;

FIG. 5 is an exploded perspective view of a fixed second shaft assemblyof the pump of FIG. 1;

FIG. 6 is a perspective view of a flow capacity control lever forrotating the second shaft of FIG. 5;

FIG. 7 is a cross-sectional view of the lever of FIG. 6 taken along thelines 7-7;

FIG. 8A is a detailed cross-sectional view of the pump of FIG. 1;

FIG. 8B is a cross-sectional view of the pump of FIG. 1, showing variousrotational axes of the device;

FIG. 8C is a schematical diagram of the pump housing showing therotation of a control plane with respect to the pump housing;

FIG. 9A is a perspective view of the pump of FIG. 1 shown with the upperhalf of the housing removed;

FIG. 9B is a front elevational view of the pump of FIG. 9A;

FIG. 9C is a top plan view of the pump of FIG. 9A;

FIG. 9D is a side elevational view of the pump of FIG. 9A;

FIGS. 10A-10E are sequenced perspective views of the pump of FIGS. 9A-9Dwith the control lever in the 0 degree position, as the input shaft ofthe pump is rotated 180 degree during the pump's operation;

FIG. 11A is a perspective view of the pump of FIG. 1 shown with theupper half of the housing removed and the control lever in a 180-degreeposition;

FIG. 11B is a front elevational view of the pump of FIG. 11A;

FIG. 11C is a top plan view of the pump of FIG. 11A;

FIG. 11D is a side elevational view of the pump of FIG. 11A;

FIGS. 12A-12E are sequenced perspective views of the pump of FIGS.11A-11D, with the control lever in the 180 degree position, as the inputshaft of the pump is rotated 180 degrees during the pump's operation;

FIG. 13A is a perspective view of the pump of FIG. 1 shown with theupper half of the housing removed and the control guide in a neutralposition.

FIG. 13B is a front elevational view of the pump of FIG. 13A.

FIG. 13C is a top plan view of the pump of FIG. 13A.

FIG. 13D is a side elevational view of the pump of FIG. 13A.

FIGS. 14A-14E are sequenced perspective views of the pump of FIGS.13A-13D, with the control lever in the 90 degree or neutral position, asthe input shaft of the pump is rotated 180 degrees during the pump'soperation.

FIG. 15 is a detailed cross-sectional view of a spherical pump operatingwith an exterior carrier guide ring.

FIG. 16 is a detailed view of the exterior carrier ring of the device ofFIG. 15.

FIG. 17 is a detailed cross-sectional view of the pump of FIG. 1 showingadded structure to improve rigidity and the addition of internalcoolant-lubricant or flushing lines.

FIG. 18 is a detailed cross-sectional view of the pump of FIG. 1 showinga different embodiment of added structure to improve rigidity and theaddition of internal coolant-lubricant or flushing lines.

FIG. 19 is a cross-sectional view of the pump of FIG. 1, showing anembodiment providing balanced forces across a secondary vane as thesecondary vane approaches the relatively closed position with respect tothe primary vane.

FIGS. 20A-20E are sequenced perspective views of the pump of FIGS. 9A-9Dwith the control lever in the 0 degree position, as the input shaft ofthe pump is rotated 180 degree during the pump's operation, showing thesimultaneous flow of two fluids through the pump.

FIG. 20F is a view of the port openings only of FIG. 20A-20E to show theflow of two different fluids.

FIG. 21 is a cross-sectional view of the pump of FIG. 1, showing theembodiments of simplified mechanism, tight tolerancing and fluidflushing to improve use of the fluid machine as a blood pump.

FIG. 22 is a front perspective view of a pump similar to FIG. 1 butshowing the embodiment of a port insert.

FIGS. 23A-23E are sequenced perspective views of the pump of FIGS. 9A-9Dwith the control lever in the 0 degree position, as the input shaft ofthe pump is rotated 180 degree during the pump's operation, showing thesimultaneous flow of two fluid streams at two different flow ratesthrough the pump.

FIG. 24 is a front perspective view of a pump similar to FIG. 1 butshowing the embodiment of an eccentric port insert.

FIG. 25 is a front perspective view of a fluid pump, shown with theupper and lower halves of the housing of the pump exploded away anddivided into quarters, and internal components of the device removed.

FIGS. 26A-26E are sequenced perspective views of the pump of FIGS. 9A-9Dwith the control lever in the 0 degree position, as the input shaft ofthe pump is rotated 180 degree during the pump's operation, showing onlythe volumes occupied by the fluid in the fluid chambers and fluid ports.

FIG. 27 is a perspective view of the secondary vane of the presentinvention, depicting a first aspect of altering the vane shape to reduceshear forces on the fluid.

FIG. 28 is a perspective view of the fluid volumes shown in FIG. 26E,showing the embodiment of the vane shape being altered according to thefirst aspect depicted in FIG. 27 to reduce shear forces on the fluid.

FIG. 29 is a perspective view of the secondary vane of the presentinvention, depicting a second aspect of altering the vane shape toreduce shear forces on the fluid.

FIG. 30 is a cross-sectional view of a port of the present inventiondepicting a third aspect to reduce shear forces on the fluid involvingaltering of the transitional surface between the housing and a port.

FIG. 31 is a graphical representation of the variation of the volumes oftwo fluid chambers as the input shaft is rotated in the pump in anembodiment for assisting or replacing the pumping of a human heart.

DETAILED DESCRIPTION

Referring to FIG. 1 of the drawings, the reference numeral 10 generallydesignates a pulsatile blood pumping system of the type that can applythe improvements of the instant invention. The pump 10 is generallysimilar in construction to the device described in U.S. Pat. No.6,241,493.

The pump 10 includes a housing 12, which is formed into two halves 14,16. Each half 14, 16 of the housing 12 is generally configured the sameas the other and has a hemispherical interior cavity 18 (FIG. 2), whichforms a spherical interior of the housing 12 when the two halves 14, 16are joined together. Each housing half or piece 14, 16 is provided witha circular flange 20 having a flat facing surface 21 which extendsaround the perimeter of the cavity 18 and which abuts against andengages the corresponding flange 20 of the other housing piece 14, 16.The flange face 21 lies in a plane that generally divides the sphericalhousing interior 18 into two equal hemispherical halves when the housinghalves 14, 16 are joined together.

A fluid tight seal is formed between the housing halves 14, 16 when thehalves 14, 16 are joined together. Formed in each housing piece 14, 16are rear and front fluid ports 24, 26 that communicate between theexterior of the housing and the housing interior 18. The fluid ports 24,26 are circumferentially spaced apart approximately 90 degrees from thenext adjacent port, with the approximate center of each fluid port beingcontained in a plane oriented perpendicular to the flange faces 21 andthat bisects the interior of the housing 12 when the housing halves 14,16 are joined together. The ports 24, 26 are positioned about 45 degreesfrom the flange faces 21 on each housing half 14, 16.

Formed at the rearward end of each housing half 14, 16 adjacent to therearward port 24 is a recessed area 28 formed in the circular flange 20for receiving a main input shaft 32 (FIG. 1), which extends for adistance into the housing interior 18. This shaft will be referred to aseither the first or the input shaft. The primary axis or axis ofrotation 33 of the input shaft 32 lies generally in the same plane asthe flange faces 21. An input shaft collar 34 extends outwardly from thehousing halves 14, 16 and is provided with a similarly flanged surface36 for facilitating joining the housing halves together.

Located at the forward end of the housing 12 opposite the collar 34 ineach housing half 14, 16 is a recessed area 38 formed in the circularflange 20 to form a shaftway for receiving a second shaft 40 (FIG. 1). Aneckpiece 42 extends outwardly from the circular flange 20 and is alsoprovided with a flanged surface 44 to facilitate joining of the housinghalves together.

The housing 12 houses primary and secondary vane assemblies 52, 54,respectively. Referring to FIG. 3, the primary vane assembly, designatedgenerally at 52, is formed into two halves 56, 58. The primary vanehalves 56, 58 are generally configured the same, each having a generallyflat inner surface 59 that abuts against the inner surface of the otherhalf. The primary vane halves 56, 58 each have opposite vane members 62,64, that are joined together at opposite ends by integral hinge portions66, 68 to define a central circular opening 69. When the primary vanehalves 56, 58 are joined together, the vane members 62 and 64 form asingle opposing vane.

The vane members 62 are each provided with an input shaft recess 60formed in the flat surface 59 for receiving and coupling to the inputshaft 32 when the vane halves 56, 58 are joined together. The primaryvane assembly 52 is rigidly coupled to the input shaft 32 so thatrotation of the input shaft 32 is imparted to the primary vane assembly52 to rotate the combined vanes 56,58 within the housing interior 18.

Similarly, the vane members 64 are provided with a second shaft recess70 formed in the flat surface 59 for receiving the second shaft 40. Thesecond shaft recess 70 is configured to allow the primary vane assembly52 to freely rotate about the second shaft 40. The outer ends of thevane members 62, 64 have a generally convex spherical lune surfaceconfiguration corresponding to the spherical interior 18 of the housing12.

The hinge portions 66, 68 are each provided with a stub shaft recess 72.A stub shaft 74 is shown provided with the hinge portion 66 of the vanehalf 56. This stub shaft 74 may be integrally formed with one of thevane halves 56, 58 or may be a separate member that is fixed in place.As is shown, the stub shaft 74 projects a distance outward beyond thehinge portion 66. The hinge portions 66, 68 are each squared or flatalong the outer side edges 73.

Referring to FIG. 4, the secondary vane assembly 54 is also shown beingformed in two halves 76, 78, each half 76, 78 being generally similar inconstruction. The secondary vane halves 76, 78 are generally configuredthe same, each having an inner surface 80, which is generally flat andwhich abuts against the inner surface of the other vane half. Thesecondary vane halves 76, 78 each have opposite vane members 82, 84,that are joined together at opposite ends by integral hinge portions 86,88 to define a central circular opening 90. When the secondary vanehalves 76, 78 are joined together; the vane members 82 and 84 form asingle opposing vane.

The vane members 82, 84 are each provided with pivot post recesses 92formed in the inner surfaces 80 of each vane half 76,78. The outermostends of the vane members 82, 84 also have a generally convex sphericallune surface configuration corresponding to the spherical interior 18 ofthe housing 12.

The hinge portions 86, 88 are each provided with a stub shaft recess 94.A second stub shaft 96 is shown provided with the hinge portion 88 ofthe vane half 78. This stub shaft 96 may be integrally formed with oneof the vane halves 76, 78 or may be a separate member that is fixed inplace. As is shown, the stub shaft 96 projects a distance inward fromthe hinge portion 88. Both the hinge portions 86, 88 are squared or flatalong the inner side edges 89 to correspond to the flat outer side edges73 of the hinge portions 66, 68 of the primary vane halves 56, 58. Theshapes of narrow ridges 83 generally complement the shape of theexterior surfaces of hinge portions 66, 68. The exterior of the hingeportions 86, 88 are in the form of a convex spherical segment or sectorthat is contoured smoothly with the curved surface of the outer ends ofthe vane members 82, 84, and corresponds in shape to the sphericalinterior 18 of the housing 12.

When the primary and secondary vanes 52, 54 are coupled together (FIG.3) and mounted to the main input shaft 32, the stub shafts 74, 96 aregenerally concentric. The stub shaft 74 of the primary vane assembly 52is received within the recesses 94 of the hinge portion 86 of thesecondary vane assembly 54 to allow relative rotation of the secondaryvane assembly 54 about the stub shaft 74. Likewise, the stub shaft 96 ofthe secondary vane assembly 54 is received within the recesses 72 of thehinge portion 68 of the primary vane assembly 52 and allows relativerotation of the primary vane assembly 52 about the stub shaft 96. Inthis way, the primary and secondary vanes assemblies 52, 54 remaininterlocked together while the secondary vane assembly 54 is allowed topivot relative to the primary vane assembly 52 about a first pivotalaxis 35 that is perpendicular to the primary axis 33 of the input shaft32.

FIG. 5 shows an exploded view of a fixed second shaft or race assembly100. The second shaft assembly 100 is comprised of the cylindricalsecond shaft 40, which is received in the recesses 38 of the housinghalves 14, 16, as discussed previously. The cylindrical second shaft 40is coaxial with the primary axis 33 of the input shaft 32 when mountedto the housing 12. At the inner end of the shaft 40 is a spherical shaftportion 102 in the form of a sphere section. Projecting from the innerside of the spherical shaft portion 102 is a cylindrical carrier ringshaft 104. The longitudinal axis of the carrier ring shaft 104 isoriented at an oblique angle with respect to the axis of shaft 40. Thisangle may vary, but is preferably between about 30 degrees to 60degrees, with 45 degrees being the preferred angle. A boss 106 projectsfrom the end of the shaft 104 to facilitate mounting of an end cap 108,which is in the form of a spherical section. The end cap 108 is providedwith a recess 110 for receiving the boss 106 of shaft 104. In theembodiment shown, a pair of threaded fasteners 112, such as screws orbolts, which are received within eccentrically disposed threaded boltholes 114 formed in the boss 106, are used to secure and fix the end cap108 to the shaft 104. Two or more fasteners may be used. Because thefasteners are eccentrically located with respect to the axis of theshaft 40, they prevent relative rotation of the end cap 108 with respectto the shaft 40.

The end cap 108 is used to secure a central carrier ring 116, which isrotatably mounted on the carrier ring shaft 104. The carrier ring 116 isconfigured with an outer surface in the form of a spherical segment sothat when the carrier ring 116 is mounted on the shaft 104 and the endcap 108 is secured in place, the combination of the spherical portion102, carrier ring 116 and end cap 108 generally form a complete spherethat is joined to the end of the shaft 40. This complete sphere isdesignated generally as central ball 115. The diameter of this spheregenerally corresponds to the diameter of the central openings 69, 90 ofthe primary and secondary vane assemblies 52, 54, respectively, to allowthe vane assemblies 52, 54 to rotate about this spherical portion of thesecond shaft assembly 100, while being in close engagement thereto. Thecarrier ring 116 is approximately centered between the spherical portion102 and the end cap 108.

The carrier ring 116 is provided with oppositely projecting pivot posts118 that project radially outward from the outer surface of the carrierring 116. The posts 118 are concentrically oriented along an axis thatis perpendicular to the axis of rotation of the carrier ring 116. Theposts 118 are received within the pivot post recesses 92 of thesecondary vane halves 76, 78 when the vane assembly 50 is mounted overthe spherical portion of the second shaft assembly 100 formed by thespherical portion 102, carrier ring 116 and end cap 108.

Coupled to the second shaft 40 opposite the spherical portion 102 is aflow capacity control lever 120 for manually rotating the shaft 40 andspherical portion 102. The control lever 120, shown in more detail inFIGS. 6 and 7, has a generally circular-shaped body portion 122. A leverarm 124 extends from the body portion 122. Formed generally in thecenter of the body portion 122 is a bolt hole 126 for receiving a bolt128 for fastening the lever 120 to the shaft 40 by means of a central,threaded bolt hole 130 formed in the outer end of the shaft 40. Spacedaround bolt hole 126 are dowel holes 132 which correspond to dowel holes134 formed in the shaft. Dowels 136 are received within the dowel holes132, 134 to prevent relative rotation of the control lever 120 withrespect to the shaft 40. Although one particular method of coupling thelever 120 to the shaft 40 is shown, it should be apparent to thoseskilled in the art that other means may be used as well. Control lever120 can have smaller profiles as shown by control lever 120A shown laterin FIGS. 9, 11, and 13. The control lever acts as an adjustable vaneguide bearing member to oscillate the secondary vane to various openingpositions relative to the primary vane.

An arcuate slot 138 that extends in an arc of about 180 degrees isformed in the body portion 122 of the lever 120 for receiving a setscrewor bolt 140. The arcuate slot 138 overlays a threaded bolt hole 142formed in the housing neck piece 42 of the housing half 14, when theshaft assembly 100 is mounted to the housing 12. The setscrew 140 isused to fix the position of the lever 120 to prevent rotation of theshaft 40 once it is in the desired position. By loosening the setscrew140, the lever 120 can be rotated to various positions to rotate theshaft assembly 100, with the setscrew 140 sliding within the slot 138.

FIG. 8A is a longitudinal cross-sectional view of the assembled pump 10shown in more mechanical detail. Although one particular embodiment isshown, it should be apparent to those skilled in the art that a varietyof different configurations and components, such as bearings, seals,fasteners, etc., could be used to ensure the proper operation of thepump 10. The embodiment described is for ease of understanding theinvention and should in no way be construed to limit the invention tothe particular embodiment shown.

As can be seen, the input shaft 32 extends through the collar 34 at therearward end of the housing 12. The collar 34 defines a cavity 144 thathouses a pair of longitudinally spaced input shaft roller bearingassemblies 146, 148. Each of the roller bearing assemblies 146, 148 iscomprised of an inner race 154 and an outer race 156, which houses aplurality of circumferentially spaced tapered roller bearings 158positioned therebetween. Spacers 150, 152 maintain the roller bearingassemblies 146, 148 in longitudinally spaced apart relationship alongthe input shaft 32, with the inner race 154 of the roller bearingassembly 148 abutting against an outwardly projecting annular step 160of the drive shaft 32, and the outer race 156 abutting against ainwardly projecting annular shoulder 162 of the collar 34.

A bearing nut 164 threaded onto a threaded portion 165 of the inputshaft 32 abuts against the inner race 154 of bearing assembly 146 andpreloads the inner races 154. Bolted to the end of the collar 34 is abearing retainer ring 166. The bearing retainer ring 166 abuts againstthe outer race 156 of bearing assembly 146 and preloads the outerbearing races 156. The retainer ring 166 also serves to close off thecavity 144 of the housing collar 34. An annular seal 168 seated on theannular lip 170 of the retainer ring 166 bears against the exterior ofthe bearing nut 164 to prevent leakage of lubricant from the bearingcavity 144.

Located within the recessed area 28 and surrounding the input shaft 32is a washer 172 that abuts against the inner race 154 of the bearingassembly 148. A compressed coiled spring 174 abuts against the washer172 and bears against a carbon sleeve 176. The sleeve 176 is providedwith an O-ring seal 178 located within an inner annular groove of thesleeve 176. The sleeve 176 abuts against a fixed annular ceramic plate180, which seats against an annular lip 182 projecting into the recessedarea 28. The low coefficient of friction between the interfacing carbonsleeve 176 and ceramic plate 180 allows the sleeve 176 to rotate withthe input shaft 32, while providing a fluid-tight seal to prevent fluidflow between the pump interior 18 and the collar cavity 144.

The input shaft 32 extends into the interior 18 of the housing 12 ashort distance and is coupled to the primary vane assembly 52 within therecesses 60 formed in vane halves 56, 58. The end of the shaft 32 isprovided with a annular collar 184 received in grooves 186 formed in therecesses 60 of the vane halves 56, 58 to prevent relative axial movementof the shaft 32 and vane assembly 52. Relative rotational movementbetween the vane assembly 52 and shaft 32 is prevented by key members188 being received in key slots of the vane assembly 52 and shaft 32,respectively.

Surrounding the second shaft portion 40 within the recess 70 of theprimary vane assembly 52 are longitudinal roller bearings 206. Seals208, 210 are provided at either end of the roller bearing assembly 206to prevent fluid from escaping along the second shaft 40 throughrecesses 70. A static O-ring seal 212 surrounds the shaft 40 at theinterface of the lever arm 120 with housing neckpiece 42 to preventfluid loss through shaftway 38.

Surrounding the carrier ring shaft 104 are roller bearing assemblies214, 216. Each roller bearing assembly 214, 216 is comprised of an innerrace 218 and an outer race 220 with a plurality of tapered rollerbearings 222 therebetween. The inner races 218 of assemblies 214, 216are spaced apart by means of a spacer 224. The inner face of the carrierring 116 rests against the outer races 220. An annular web 226 projectsradially inward from the inner annular face of the carrier ring 116 andserves as a spacer between the outer races 220 and prevents axialmovement of the carrier ring 116 along the shaft 104. For spherical pumpconfigurations that have the equivalent to carrier ring 116 on theoutside of housing 12, the equivalent ring is preferably manufactured intwo or more sections to allow ease of assembly of the pump. Thesesections may be, for example, two semicircular segments that divide theequivalent ring approximately across the diameter, or two circularsegments that join at the center circumferential plane of the equivalentring. The sections are then joined with fasteners.

Lip seals 230, 232 provided in inner faces of the end cap 108 andspherical portion 102, respectively, engage the side edges of thecarrier ring 116 to prevent fluid from entering the annular spacesurrounding the carrier ring shaft 104 where the bearing assemblies 214,216 are housed and which contains a suitable lubricant for lubricatingthe bearing assemblies 214, 216. At lower rates of rotation a lubricantor coolant may not be needed on a continual basis.

Axially oriented roller bearings 234 surround the pivot posts 118 toallow the secondary vanes 54 to rotate. Fluid seals 236 are provided atthe base of posts 118. Radially oriented thrust bearings 238 located atthe terminal ends of posts 118 and are held in place by thrust caps 240.The thrust caps 240 are held in place within annular grooves 242 formedin the pivot post recesses 92.

As can be seen, the outer ends of the primary vanes 52 and secondaryvanes 54 are in close proximity or a near touching relationship toprovide a clearance with the interior 18 of the housing 12. There isalso a slight clearance between the spherical end portion of the fixedsecond shaft assembly 100 and the central openings 69, 90 of the primaryand secondary vanes 52, 54. These clearances should be as small aspossible to allow free movement of the vanes 52, 54 within the interior18, while minimizing slippage or fluid loss across the clearances, andto allow for differences in thermal expansion between the housing 12,the vanes 52, 54 and the spherical portion 102 and end cap 108.

FIG. 8B illustrates the relationship of the various rotational axes ofthe pump components. As shown, carrier ring 116 rotates about thecarrier ring axis 246. The axis 246 intersects the primary vane axis 33at an oblique angle and defines a control plane 247. The secondary vane54 pivots about the pivot posts 118 about a secondary vane secondpivotal axis 245 that remains perpendicular to the carrier ring axis246. This second pivotal motion of the secondary vane is simultaneouswith the pivotal motion of the secondary vane about the first pivotalaxis perpendicular to the primary axis, which was discussed earlier.

FIG. 8C shows an end view of the pump 10 as viewed along the primaryaxis, and showing the various orientations of the timing or controlplane 247 that may be achieved by rotating the second shaft assembly100, as is described below.

Referring to FIGS. 9-14, the pump 10 is shown with the upper housing 16removed to reveal the internal components of the pump 10. The ports 24,26 of the upper housing 16, however, are shown to indicate theirrelative position if the upper housing 16 were present. Further,although the input shaft 32 may be rotated in either a clockwise orcounterclockwise direction, for purposes of the following descriptionthe operation of the pump 10 is described wherein the input shaft 32 isrotated in a clockwise direction, as indicated by the arrow 244 in FIG.9A.

Referring to FIGS. 9A-9D, the pump 10 is shown with control guide 120Arotated so that the carrier ring or secondary axis 246 is oriented at a45 degree angle to the right of the primary axis 33, as viewed in FIG.9C, so that the control plane 247 (FIGS. 8B and 8C) lies in asubstantially horizontal plane that is generally the same or parallel tothe plane of the flanges 20 which bisect the housing 12.

FIGS. 9A-9D show the primary and secondary vanes 50, 98 with thesecondary vane 98 at a central intermediate position of its stroke. Theforward port 26 of the upper housing 16 and the rearward port 24 of thelower housing 14 serve as discharge ports, while the rearward port 24 ofthe upper housing 16 and the forward port 26 of the lower housing 14serve as intake ports. The primary and secondary vanes 50, 98 divide thespherical interior 18 of the housing into four chambers, as defined bythe spaces between the primary and secondary vanes 50, 98 designated at248, 250. Although not visible, corresponding spaces or chambers wouldbe present in the lower housing half 14.

FIGS. 10A-10E show sequenced views of the pump 10 in operation with thecontrol lever 120 in the 0 degree position as the input shaft 32 isrotated through 180 degrees of revolution. For ease in describing theoperation, the opposing secondary vanes are labeled 98A, 98B, with theopposing primary vanes being designated 50A, 50B. As shown in FIGS. 9Aand 9C, as the input shaft 32 is rotated, the primary and secondaryvanes assemblies 52, 54 are rotated about the primary axis 33 within thehousing interior 18. Because the secondary vane assembly 54 is pivotallymounted to the carrier ring 116 by means of pivot posts 118, thesecondary vane assembly 54 causes the carrier ring 116 to rotate on thecarrier ring shaft 104 (not shown) about the carrier ring axis 246.Because the carrier ring axis 246 is oriented at an oblique angle withrespect to the primary axis 33, the carrier ring 116 causes eachsecondary vane 98A, 98B to reciprocate or move back and forth between afully open position and a fully closed position.

FIG. 10A shows the pump 10 with the secondary vane 98A in the fullyclosed position with respect to primary vane 50A. In the fully closedposition, the secondary vane 98A abuts against or is in close proximityto the primary vane 50A, so that the volume therebetween is minimal. Incontrast, with respect to the opposing primary vane 50B, the vane 98A isin a fully open position so that the space between the vanes 98A and 50Bis at its maximum. Any fluid within the space between vanes 98A, 50A ismostly fully discharged through the port 26 of the upper housing. Thereis a slight overlap or communication of the interfacing primary andsecondary vanes 50A, 98A with the port 26 along its edge when in thefully closed position to accomplish this. In one aspect of the inventionthe primary vanes 50A, 50B are sized to completely cover and seal theports 24, 26 so that slight rotation beyond this point causes theprimary vanes 50A, 50B to close off communication with the chambers 248,250 momentarily during rotation.

FIG. 10B illustrates the pump 10 with the shaft 32 rotated approximately45 degrees from that of FIG. 10A. Here the secondary vane 98A begins tomove to the open position with respect to the primary vane 50A. Thisdraws fluid into the opening space through the lower inlet port 26 ofthe lower housing 14. The secondary vane 98B also begins to move to theclosed position with respect to the primary vane 50A. Fluid located inthe chamber between the primary vane 50A and secondary 98 is thuscompressed or forced out of the upper discharge port 26 of the upperhousing 16.

In a like manner, fluid located between the secondary vane 98A andprimary vane 50B is discharged through the lower port 24 (not shown) ofthe lower housing 14, as the secondary vane 98A begins to move to theclosed position with respect to the primary vane 50B. Fluid is alsodrawn through the inlet port 24 of the upper housing 16 as the secondaryvane 98B is moved towards an open position with respect to the primaryvane 50B.

FIGS. 10C and 10D show further rotation of the shaft 32 in approximately45-degree increments. When the second shaft assembly 100 is in the 0degree position, the timing is such that the chambers created by theprimary and secondary vanes 50, 98 remain in continuous communicationwith ports 24, 26 during generally the entire stroke of the vane 50between the closed and open positions. In this way fluid continues to bedrawn into or discharged from the chambers as the secondary vanes 98 aremoved to either the open or closed positions during rotation of theshaft 32.

FIG. 10E shows the pump 10 after the shaft 32 is rotated 180 degrees.The secondary vane 98B is in the fully closed position with respect tothe primary vane 50A, just as the secondary vane 98A was when the shaft32 was at the 0 degree position in FIG. 10A. By continuing to rotate theshaft 32, the process is repeated so that the fluid is taken into thepump, pressurized and discharged by the reciprocation of the secondaryvane between the open and closed positions, which is caused by therotation of the carrier ring 116 about its oblique carrier ring axis246.

By rotating the fixed second shaft assembly 100 to different fixedpositions, the flow of fluid through the pump 10 can be adjusted andeven reversed without changing the direction of rotation of the inputshaft 32. FIG. 11A shows the pump 10 with control guide 120A rotated sothat the carrier ring axis 246 is oriented at an approximately 45 degreeangle to the left of the primary axis 33, as viewed in FIG. 11C, orabout 90 degrees from that orientation of the axis 246 as shown in FIG.9C. In this position, the control plane 247 lies in a substantiallyhorizontal plane that is generally the same or parallel to the plane ofthe flanges 20 which bisect the housing 12.

In the configuration of FIGS. 11A-11D, the forward port 26 of the upperhousing 16 and the port 24 of the lower housing 14 serve as intakeports, while the port 24 of the upper housing 16 and the port 26 of thelower housing 14 serve as discharge ports.

FIGS. 12A-12E show sequenced views of the pump 10, with the controllever 120 rotated to the 180 degree position, as the input shaft 32 isrotated through 180 degrees of rotation. In FIG. 12A, the pump 10 isshown with the secondary vane 98A in the fully closed position againstthe primary vane 50A. The vane 98A is also in a fully open position withrespect to primary vane 50B. Referring to FIG. 12B, as the input shaft32 is rotated, as shown by the arrow, the secondary vane 98A begins tomove to the open position with respect to the primary vane 50A. Thespace or chamber formed between the secondary vane 98A and vane 50A isin continuous communication with the port 26 of the upper housing 16 asit is moved to the open position. The increasing volume of this chamberas the shaft 32 is rotated, as shown in FIGS. 12C and 12D, draws fluidthrough the upper forward port 26. As this is occurring, the secondaryvane 98B moves to the closed position with respect to the primary vane50A forcing fluid between these vanes 98B, 50A through the forward port26 of the lower housing 14.

FIG. 12E shows the pump after the shaft 32 is rotated 180 degrees. Thesecondary vane 98B is now in the closed position with respect to theprimary vane 50A so that the process can be repeated. With the lever 120in the 180 degree position, fluid is also discharged through rearwardport 24 in the upper housing 16 and introduced through rearward port 24of the lower housing 14 in the similar manner as that already describedwith respect to the forward ports 26. The ports 24, 26 remain ingenerally constant communication with one of the chambers created by thevanes 50, 98 during the entire stroke of the vane 98 between the openand closed positions.

FIGS. 13A-13D illustrate the pump 10 in an intermediate or neutral mode,with control guide 120A oriented so that the carrier ring axis 246 liesin a plane perpendicular to the housing flanges 20 and is oriented at anangle of 45 degree below the primary axis 33, as viewed in FIG. 13D. Inthis orientation, the control plane 247 is in the 90 degree or verticalposition, as seen in FIG. 8C. In this mode, the ports 24, 26 onlycommunicate approximately 50% of the time with the chambers created bythe vanes 50, 98.

FIG. 14A shows the secondary vane 98 in a center or intermediateposition, with the primary vane 50 oriented so that it covers and sealsthe ports 24, 26. As the input shaft 32 rotates from this intermediateposition, as shown in FIG. 14B, the port 26 of the upper housing 16begins to communicate with the chamber between secondary vane 98B andprimary vane 50A, and the port 26 of the lower housing 14 communicateswith the chamber between the secondary vane 98A and primary vane 50A. Asthe secondary vane 98B is moved towards the open position with respectto the primary vane 50A, some fluid is drawn through the port 26 of theupper housing 16. In a similar manner, the secondary vane 98A is movedto the closed position with respect to the primary vane 50A so fluidtherein is forced out of the lower port 26.

FIG. 14C shows the secondary vane 98B in the fully open position withrespect to the primary vane 50A. The secondary vane 98A, which is hiddenfrom view, is in the fully closed position with respect to primary vane50A, with the closed space between the primary vane 50A and secondaryvane 98A being in communication with the lower forward port 26 of thelower housing 14.

As the shaft 32 is rotated further, as seen in FIG. 14D, some fluid isforced out of the upper housing 16 through port 26 as the secondary vane98B now moves to the closed position with respect to vane 50A. Fluid isalso drawn in through the lower port 26 as the secondary vane 98A ismoving to the open position in relation to the primary vane 50A.

FIG. 14E shows the pump 10 after rotation of the shaft 32 180 degreesfrom its original position of FIG. 14A. The secondary vane 98 is onceagain in the intermediate position, like that of FIG. 14A, and theprocess is repeated. With the control lever 120 in the 90 degreeposition, as described, the ports 26 of the lower and upper housing 14,16 only communicate with the chambers defined by the primary andsecondary vanes 50, 98 approximately 50% of the time. This results inequal volumes of fluid being both drawn and discharged through each ofthe forward ports 26 in the upper and lower housing during this neutralmode. The operation is the same with respect to the fluid flow throughthe rearward ports 24 in the lower and upper housing 14, 16. The netfluid flow through the pump 10 is therefore essentially zero.

By rotating the control lever 120 between the 0 degree and 180 degreepositions, the fluid flow can be increased or decreased precisely in asmooth and continuous manner, and can be directed in either flowdirection. This is due to the increased amount of time that the inletports and discharge ports communicate with the chambers 248, 250 formedby the vanes 50, 98 during the expansion and compression strokes,respectively, of the secondary vane 98. Thus, for example, as the lever120 is rotated from the 90 degree or neutral position towards the 0degree position of FIG. 10A, the length of time the forward port 26 ofthe upper housing 16 communicates with the chamber formed by the primaryvane 50A and secondary vanes 98, as the secondary vanes 98 are moved tothe closed position, is lengthened, resulting in more and more fluidflow through this port. As described previously, when the lever is atthe full 0 degree position, the port 26 of the upper housing 16 is incommunication with the chamber formed by the primary vane 50A andsecondary vanes 98 during almost the entire compression stroke of thesecondary vanes 98 with respect to the vane 50A so that full flow isachieved when the pump 10 is in this mode. Similar results in thereverse-flow direction are achieved by rotating the lever 120 betweenthe 90-degree and the 180-degree position, which is shown in FIG. 12A.

Other means could be provided for rotating the second shaft assembly100. For instance, the shaft 40 could be coupled to a worm and worm gearto rotate the second shaft to various positions. This in turn could becoupled to a controller that would cause the second shaft assembly to berotated to automatically control and adjust the fluid flow or capacityof the pump 10. In this manner the flow capacity and even the directionof flow can be automatically adjusted remotely from the pump. A pumpconfigured with this aspect of control of the second shaft assemblyposition can be seen in FIGS. 22, 24, and 25, where controller 119 turnsworm gear 121 to rotate gear 120C attached to shaft 40. It should berecognized that other controller implementations could be used forremote control of the fixed shaft.

The pump described above is based on an internal carrier ring assemblythat guides the reciprocating action of the secondary vane. Alternately,these types of spherical pumps can have the guide carrier ring mountedin an exterior manner. U.S. Pat. No. 5,199,864 discloses a somewhatsimilar pump to that of U.S. Pat. No. 6,241,493 and also describes anembodiment (the “second embodiment”) that uses an exterior carrier ringto guide the reciprocal motion of the vanes. In one particularalternative embodiment (the “second” embodiment) which is illustrated inFIGS. 15-16, a larger diameter collar 312 having inwardly protrudingspindles 387 and 388 serves as the means for controlling reciprocationof secondary member 330 relative to rotation of primary member 320. Theinside diameter of collar 312 matches the inside diameter of thespherical interior surface 274 of housing 370 in order to provide aflush spherical surface. The housing 370 is modified to define anangular raceway 400 between two halves of housing 370 for receivingcollar 312 therein. Also received within raceway 400 are washer-likebearings 385 and 386 for enabling rotation of collar 312 within raceway400. The housing 370 is formed in two halves that are joined byconventional means along raceway 400 for enabling assembly of collar 312and bearings 385 and 386 within raceway 400. A central member 333provides the pivotal engaging surface between primary member 320 andsecondary member 330.

The other features of the structure and operation of this externalcarrier ring design are substantially the same as in U.S. Pat. No.6,241,493 except, of course, changes in the interior surfaces of vanes321, 322, 331 and 332 are preferably modified to accommodate centralmember 133. Similarly, the housing 370 of the second embodiment ismodified to accommodate for raceway 400 therein, to produce theconstruction shown in FIG. 15. Many of the improvement embodiments ofthe instant invention have application in this type of exterior carrierring design also.

The use of the prior art machines as described earlier was limited inits use as a blood pump, in that they either provided an undesirablycomplex mechanism and/or did not adequately address issues related toblood clotting. One key to avoiding clotting is to eliminate areas whereblood flow can become stagnant. The instant invention is quite useful inthat all or nearly all of the volume of a fluid chamber is expelled witheach relative opening and closing of primary and secondary vanes,insuring that blood flow cannot become stagnant in the fluid chamber.Additionally, the surface of spherical interior 118 of housing 12 iscontinually being swept by the motion of the exterior portions of vanes52, 54, and the mutually facing surfaces of vanes 52, 54 are repeatedlybrought within close proximity to each other with every oscillatingmotion of secondary vane 54. In short, there is no blood-contactingsurface within the housing 12 of pump 10 whereon flow can becomestagnant, which feature greatly aids in the prevention of thrombosis. Ina first embodiment for preventing blood clotting, FIG. 21 shows asimplified rotating mechanism adapted from the embodiment shown in FIG.17. In this embodiment, the rotation of carrier ring 116 about thecarrier ring axis is optionally slidingly facilitated by washer-shapedbearings 117A, 117B. To prevent the clotting of blood, which clots canmigrate to other areas of the blood stream (thromboembolisms), the gapbetween carrier ring 116 and spherical shaft portion 102 and the gapbetween carrier ring 116 and end cap 108A, or optionally the gapsbetween the carrier ring 116 and bearings 117A, 117B and the gap betweenbearing 117A and spherical shaft portion 102 and the gap between bearing117B and end cap 108A are preferably less than the approximate diameterof a red blood cell. Additionally, the gap between the cylindricalsurfaces of pivot posts 118 and the corresponding recesses 92 ofsecondary vane halves 76, 78 is preferably less than the approximatediameter of a red blood cell. As can be seen, many of the moving partsshown in FIG. 17 have been removed or replaced in this embodiment, e.g.bearings 222 and fasteners 122, the latter of which have been replacedby threads 108B included on carrier ring shaft 104 to receive modifiedend cap 108A in a manner taught by Stecklein in U.S. Pat. No. 5,199,864.This simpler mechanism reduces the complexity of the pump design, and isfacilitated by the fact that the pump of the instant invention has arelatively low rotation rate of the input shaft 32, and alternativelymay also be employed with the carrier ring on the outside of the housinginterior, also as taught by Stecklein in U.S. Pat. No. 5,199,864.

In a second embodiment for preventing blood clotting, FIG. 17 shows amechanism for continuously flushing, cooling and/or lubricating movinginterfaces of the instant invention, with a fluid flushing line runningthrough the input shaft, filling the interior sections of the centralball 115, including one or more of the moving interfaces, and thenflowing out through fixed shaft 40. This is shown as the dark linesbeginning at point 137 and exiting shaft 40 at point 139. Alternatively,this fluid could flow in the opposite direction, feeding in throughshaft 40 and out through point 137. The flushing fluid could be blood,blood plasma, or any of the various fluids known to be compatible withthe human biological system, and could be supplied from fluid chamberswithin pump 10, from external connections to the vascular system, orfrom sources external to the body. Being biocompatible with therecipient, the flushing fluid could flow in limited amounts into thebloodstream of the recipient without adverse effects. This flushingmechanism may also be readily implemented in the simplified embodimentdepicted in FIG. 21.

The use of the prior art machines as described earlier was also limitedin its use as a blood pump, in that they cause excessive shear forces onthe fluid as the fluid flows through the pump. One depiction of suchexcessive shear forces is provided in FIGS. 26A-26E, which approximatelycorrespond to FIGS. 10A-10E of the description of the prior art, showingonly the fluid volumes defined by chambers 301-304, as described ingreater detail below with reference to FIGS. 20A-20E, and the upper andlower port fluid volumes 24A, 26A are defined by the interior of upperand lower ports 24, 26 respectively. As the input shaft 32 (not shown)rotates about its axis in the clockwise direction as shown in FIG. 20A,the fluid chamber 304 decreases from its maximum volume depicted in FIG.26A near to its minimum volume as depicted in FIG. 26E. As the volume offluid chamber 301 approaches its minimum, fluid in chamber 301 nearupper port fluid volume 26A necessarily has a greater velocity (depictedby size of arrow 313) than the velocity 311 of the fluid furthest fromupper port fluid volume 26A. This is because of the fact that thecross-sectional area provided perpendicular to the direction of fluidflow 313 near the port is roughly the same as the cross-sectional areaprovided perpendicular to the direction of fluid flow 311, while thecumulative flow of all points further from the port than the location of313 pass through the position near arrow 313. This greater velocity 313near the port interacts with the vane walls in a way that createsincreased shear forces on the fluid in the vicinity of arrow 313.

To reduce the shear forces just mentioned, it is necessary to modify oneor more surfaces of the vane from the standard shape taught in the priorart, which will be characterized generally as an “orange section”, withtwo main planar faces that generally mate with faces on opposing vanes.In the aspects of sheer reduction hereafter mentioned involvingalteration of the vanes, said alteration is generally a modification on(or of) at least one of the said vane faces. A first aspect of theinstant invention that reduces the above-mentioned shear forces providesvane shapes such that the distance between proximal primary vane andsecondary vane at locations nearer the port are greater than thedistance between proximal primary vane and secondary vane at locationsfurther from the port. One depiction of this embodiment is shown in FIG.27, where a vane face of secondary vane 98B is altered according tosurface 306, where the plane of the surface of secondary vane 98B facingthe surface of primary vane 50A has been rotated slightly about an axiswhich is coincident with both point 241 and the center point of centerball 115, with the original surface 305 being represented with dottedlines for comparison. As shown in FIG. 28, the fluid near upper port 26Ahas a decreased velocity 312A, and therefore a decreased shear rate inthe fluid at that location.

With reference to FIG. 29, a second aspect of the instant invention forreducing shear forces alternatively provides at least one channel 307 inthe vane surface 305, which channel allows fluid at points removed fromthe port to flow along paths 308A and 308B which are relativelyperpendicular to and shorter than the more direct paths 309 along thesurface 305 to the discharge port. The above two embodiments may becombined by providing channels 307 whose depth is tapered so that thedepth of the channel 307 at a point closer to the port is deeper thanthe depth of the channel 307 at a point further from the port. Likewise,channel 307 can be tapered in its width so that it is larger near theport. As would readily be apparent to those skilled in the art, the sameobjective of reducing shear forces on blood as described above may beobtained by any of a variety of combinations of modifications in theshape, size or surfaces of primary vanes 50A, 50B and secondary vanes98A, 98B.

With reference to FIG. 30, a third aspect of the instant invention forreducing shear forces additionally provides a curvilinear taperedportion 25 of one or more ports 24, 26 to reduce shear due totransitions between the housing surface and the interior of the port.Reduction of shear forces on fluid flowing between the housing interior18 can be provided by a variety of different transitions between thehousing interior 18 surface and the interior surface of the ports 24, 26as would be apparent to those skilled in the art.

The present invention improves greatly over prior art devices in its useas an artificial heart or heart assist device. In one embodiment of thepresent invention, pump 10 is used as an internally implanted orextracorporeally connected assist or replacement to one or bothventricles of the human heart. In a preferred embodiment, pump 10 issized to provide flow and pulsation rates that match the typicalrequirements of the recipient. In one example of this particularembodiment, and with reference to FIGS. 1, 3, 4, 21, a blood pumpingsystem is sized to provide pulsatile flow for a recipient whose normalrequirements are approximately five liters of blood flow per minute at aresting heart rate of 70 beats per minute. The pump of this example isformed with housing interior 18 of inside diameter 6.75 cm, center ball115 of diameter 3.15 cm, an input shaft 32 of diameter 1.0 cm, secondaryvane integral hinge portion 86 outside diameter of 3.75 cm and thicknessof 0.5 cm in the vicinity of and axial direction of stub shaft 74,primary vane semicircular hinge portion 66 thickness of 0.675 cm in theradial direction of stub shaft 74, oblique angle of 45 degrees betweenlongitudinal axis of the carrier ring shaft 104 with respect to the axisof fixed shaft 40, angle 321 of 44 degrees that the cross-sectionalpoints nearest center ball 115 that the primary vanes 56, 58 andsecondary vanes 76, 78 make with center of ball 115, and face angle 322of 7 degrees that the vane faces make with respect to line 323 whichintersects the center of ball 115 and the corner of the cross-section ofprimary vane nearest center ball 115. With this combination thepulsatile spherical pump of the instant invention can supply therequired five liters/minute flow using input shaft rotational speeds ofapproximately 35 rpm, which rotational speed would also provideapproximately 70 pulsatile “beats” per minute. This can be compared torotational speeds of 4000-8000 for some current heart pumps.

For this embodiment, the materials of construction for the pump areselected from those known to have a high degree of hemocompatibility andbiocompatibility in living systems, such materials including but notlimited to titanium, pyrolytic carbon, Dacron, heparin, polyvinylpyrrolidone- and polyacrylamide-based polymers, polyurethanes, andphosphorylcholines. In addition to these basic materials of constructionsome coatings can be applied to blood contacting surfaces or materialsthat can be added to the blood flowing through the system to increasethe hemocompatibility of the blood-biomaterial interface. The materialsso used include heparin, heparin proteoglycans,polyethylene-glycol-diisocyanate, saratin, clopidogrel (Plavix),triazolopyrimadine, prostaglandins, prostacyclin, prostaglandin E1,acenocoumarol (Sintrom; Novartis Pharma, Vienna, Austria),acetylsalicylic acid (aspirin) and derivatives of any of the foregoing.

For the case of this embodiment with internal implantation, the pump isimplanted into the chest or abdominal cavity of the recipient andanchored in place by attachment via fasteners or tethers to the bones,muscles, sinews, and/or internal organs of the recipient. The surfacesof the pump may be either smooth or optionally porous to provideingrowth of host cells to further anchor to and providehemocompatibility and/or biocompatibility within the body. For a casewhere pump 10 is used as a biventricular assist device (biVAD), two eachof ports 24, 26 of pump 10 are provided two inlet connections and twooutlet connections for a total of four connections, which in turn areconnected to the left and/or right ventricle, left and/or right atrium,aorta, pulmonary artery and/or another systemic or pulmonary artery orvein as best suited for the needs of the individual's case, and basedupon whether the device is being used as a partial assist or totalreplacement for one or both ventricles of the heart. As a totalreplacement for both ventricles the four chambers of pump 10 provideunique equivalence in many ways to the four chambers of the heart. Theflow rate of the device of this embodiment may be controlled by anycombination of control of rotation rate of primary vane 52 or by meansof flow control 124. For the latter in the case of internalimplantation, the flow control 124 is preferably modified to a smallerprofile from that shown in FIG. 1. An example of the smaller profile120A is shown for example in FIGS. 9, 11, and 13. For the case where anelectrical motor turns input shaft 32, the motor may either be attachedlocally to pump 10, or the motor may optionally be located remotely frompump 10, and connected to input shaft 32 via a rotary coupling or cable.Such remote operation may be desirable when there are space constraints,(e.g., in a small child) or to relocate the heat that may be generatedby the motor remotely from pump 10.

As an alternative to the use of an external motor, the movement of vanes52 and/or 54 can be powered electromagnetically. In this aspect, vanes52 and/or 54 have, for example, permanent magnets imbedded in or on themin a way that does not interfere with the biocompatibility orhemocompatibility of pump 10. The vanes modified in this way are thenmoved via, for example, an electromagnetic field that is applied fromwithin or external to the housing. This field is then sequenced inprogressive locations in such a way as to maintain motion of vanes 52,54 and therefore the pumping action of pump 10. In this aspect, inputshaft 32 may be passive rather than a transferring member of the motivepower, and may penetrate only the interior wall of housing 12 and endprior to penetrating the exterior surface of housing 12. Such aconfiguration may be advantageous in terms of compactness, which isdesirable from the standpoint of implantation, as well as advantageousin reduction of the number of moving parts and simplification ofmanufacture, both of which are desirable in terms of reliability andcost. As another variation of this aspect with the carrier ring mountedexternal to spherical interior 18 in a manner similar to that describedabove for FIGS. 15-16, the carrier ring can be used as a stator toeffect movement of secondary vane 54, which due to the previouslydescribed coupling to primary vane 52 via first and second pivotal axesboth rotates the primary vane 52 and secondary vane 54 and causes thepivotal oscillation of secondary vane 52 with respect to primary vane54, and pumping action with respect to inlet ports 24, 26 and dischargeports 24, 26 as described previously. With proper placement of saidembedded magnets in vanes 52, 54 and appropriately configured magneticfields from within or from outside of housing 12, rotation of primaryvane 52 can be effected about primary axis 33, without the need forinput shaft 32 to penetrate the interior wall of housing 12, and withoutthe need for a carrier ring within spherical interior 18 or a carrierring external to spherical interior 18. With this combination of properplacement of magnets and configuration of magnetic fields, the rotationof primary vane 52 about rotational axis 33 is stably maintained by saidcombination, and the pivotal oscillation of secondary vane 54 relativeto primary vane 52 is also stably maintained by said combination. Thishas the dual advantages of reducing friction and reducing surfaceinterfaces that may otherwise tend to difficulties in avoidingthrombosis.

The pulsatile blood pumping system can also be configured in a modewherein the motor for rotating the first shaft is physically detachedfrom the housing of the pump but either mechanically orelectromagnetically linked to the first shaft. In this aspect of theinvention the detached motor could be implanted in an abdominal cavitywhile the pumping system is implanted in the chest cavity of a livingorganism. Alternately the power required to rotate the first shaft canbe supplied from outside the body (transcutaneously) by techniques suchas radio frequency power transmitted across a receiving coil or viamagnets coupled across a recipient's skin surface or through the skin(percutaneously) via an electrical line, mechanical cable or pneumatictubing.

For the case of this embodiment with external use, the pump is locatedexternal to the recipient and mounted on a suitable carrier that ispreferably mobile. Blood fluid is circulated with the inventive deviceto and from the recipient. The surfaces of the pump are preferablytemperature controlled. Pump 10 can be configured as a biVAD in a mannersimilar to that described above for an implanted device, or can beconfigured to assist or replace one or both ventricles. The motor mayeither be attached locally to pump 10, or the motor may optionally belocated remotely from pump 10, and connected to input shaft 32 via arotary coupling or cable and/or a magnetic coupling. Such remoteoperation may be desirable to isolate heat generated by the motor awayfrom the pump. Alternatively, thermal isolation may be accomplishedusing insulating material between the motor and pump. Also, in thiscase, ports can be relatively conveniently modified using changeableinserts as described for FIG. 24 below.

For the case of this embodiment where the vanes 56, 58, 76, 78 aresimilar in dimensions, FIG. 31 depicts the variation of the volume (inmL) of fluid chambers 301 (curve 444), and 302 (curve 888) as primaryvane 52 is rotated about the axis of input shaft 32. As previouslyexplained herein, however, alterations can independently providedifferences in flow rates through one or more of the fluid chambers.Returning to the specific case depicted in FIG. 31, the volumes of thechambers 301, 302 vary sinusoidally with a maximum volume of 36.2 ml asthe primary vane 52 is rotated one full revolution (2×π radians) aboutthe axis of input shaft 32 at a rate of 35 rpm. In this embodiment, theoutput flow of chambers 301, 303 have coincident peaks and troughs andare provided with a first common outlet, and the output flow of chambers302, 304 have coincident peaks and troughs and are provided with asecond common outlet. Such combined output and input flows may beuseful, for example in the case where pump 10 is being used as a leftventricular assist device (LVAD) or as a right ventricular assist device(RVAD). Separating the two inlet flows and two outlet flows would ofnecessity provide a different transient flow profile, while notdetracting from their pulsatile nature. Since the volume variations haveoffset timings as depicted by distance 390 in FIG. 31, the flow ratesalso vary with offset timings, and the depicted embodiment provides twoflow pulses of 72.4 ml, one each from the first and second commonoutlets, with each revolution of the primary vane 52 about the inputshaft 32, giving an average flow rate of about 5 liters per minute, andapproximating a heart beat rate of 70 pulses or “beats” per minute,which matches the normal requirements of the example recipient above.Both flow rate and pulsation rate can be increased to the maximumanticipated need of the recipient by increasing the rate of rotation ofinput shaft 32. In the preferred embodiment for the case of the pumpbeing used to assist or replace both ventricles, the output from thefour chambers is separated and the ratio of magnitudes of flow throughthe first and second outlets is adjusted as described in the paragraphsbelow to better reflect the natural difference between the flow of theright and left ventricles of the heart, which is typically about 20%higher in the left ventricle. In this preferred embodiment for assistingor replacing both ventricles, the present invention can provide thedistinction of providing two substantially simultaneous pulse peaks(discharge surges) from the same device, which is highly advantageousfrom a physiological standpoint. Additionally, the device provides twosubstantially simultaneous pulse troughs (intake surges), which is alsohighly advantageous. Furthermore, the device provides at least one pairof simultaneous intake and discharge streams. In an optional embodimentwhen this device is used as a heart assist device or ventricular assistdevice, electronic sensors and control circuitry is used to time thepump rotation so that flow pulsations delivered by pump 10 coincide,with or without peak-to-peak offset, flow pulsations of one or both ofthe heart ventricles of the recipient. Still further, the shape of atransient flow curve corresponding to any chamber of pump 10 may bemodified by appropriately placing a flow element with capacitive (e.g.,elastic properties) and/or resistive characteristics in communicationwith said chamber. It is apparent without further explanation, that thisembodiment providing a pump capable for being used as an artificialheart or heart assist device may also include any combination offeatures of the above- and below-mentioned embodiments to reduce shearstresses on the blood being pumped through the machine, vary the ratioof flow rates between chambers, flush components and/or provide tighttolerances between moving parts.

A significant advantage of this embodiment of the present invention isthat it does not require valves in the traditional sense. Valves ofprior art artificial hearts are prone to wearing out and to becomingcalcified, which are both disadvantageous for a life-sustaining device.Another advantage of the present invention is that it can be sized tomatch both the normal flow rate and provide the pulsatile flow thatmimic the natural characteristics of the recipient's heart. Anotheradvantage is that the present invention can be operated at relativelylow rpm, simplifying motor requirements and reducing the potential forwear of moving parts. Still another advantage is the relatively smallsize of the pump.

For use as a blood pump the pulsatile blood pumping systems withinternal carrier rings described as part of the instant invention canhave alternate designs with respect to the internal sphere. One designis to have is no contact between the vanes and both the internal sphereand the housing of the machine. With no internal contact between thoseinternal components the pulsatile blood pumping system just describedhas the potential for long life during use. In constant use howeverinstabilities can occur that result in vibration of the internalstructures, causing for example unwanted interference between theexterior surfaces of vanes 52, 54 and the interior of housing 12 and/orthe exterior surfaces of spherical portion 102 and the end cap 108.Accordingly a second design provides for improved rigidity of theinternal structure of the pump. FIG. 17 shows this second design thatsignificantly improves the rigidity of the internal structure of thepump. At the interior end of rotating shaft 32 a nipple 133 is extendedinto the end cap 108 and rotatably attached by means of a suitablebearing assembly (not shown). This extended nipple providessignificantly improved rigidity to the design without significantlyincreasing the load on the rotating shaft. The extended nipple alsoallows the inclusion of a pathway for a lubricating coolant fluid or aflushing fluid to and through the central ball 115. Alternately thedesired rigidity can be supplied by an extension 135 from the centralball 115 attached rotatably to input shaft 32 as shown in FIG. 18. Itshould be recognized that the rigidity desired from this change couldalso be achieved by related mechanical implementations, such as a sleeveextending from the central ball 115 and encircling the input shaft 32with appropriate bearing assembly to maintain the shaft as rotatable, orsuch as a rotatable coupling between the primary vane 50A and end cap108. These latter two versions of the rigidity solution are not shown inthe drawings.

In another embodiment to inhibit fluid leakage between chambers sealsare provided between the two vanes and the central ball and seals arealso provided between the two vanes and the pump housing. Also toinhibit fluid leakage and with reference to FIG. 3 and FIG. 4,preferably seals are provided (but not shown) between the stub shaft 74and the recesses 94; likewise seals are provided (but not shown) betweenthe stub shaft 96 and the recesses 72, between the outer side edges 73of primary vane halves 56, 58 and inner side edges 89 of secondary vanehalves 76, 78, and between narrow ridges 83 of the secondary vane halves76, 78 and the hinge portions 66, 68 of primary vane halves 56, 58. Itshould be recognized that such seals could be made from high performanceplastic or elastomeric materials. Alternatively, the seals of thisembodiment may be brush seals or labyrinth seals, both of which arecommonly known.

The use of the prior art machine as described earlier was limited inthat it did not provide for balancing forces upon the secondary vane asit neared the relatively closed position with respect to the primaryvane. As shown in FIG. 19, secondary vane 98B is approaching therelatively closed position with respect to primary vane 50B. Thepressure of the fluid being pressurized in chamber 301 exerts a forcedepicted in the general direction 101, which pressure force was notbalanced in prior art machines by the force depicted in the generaldirection 103 which latter force is due to the slowing of momentum ofsecondary vane 98B. In an embodiment of the present invention, theweight or density of secondary vane 98B is adjusted to balance momentumforce 103 with pressure force 101, which lowers the wear on theinterfacing surfaces and bearings between secondary vanes 98A, 98B andthe carrier ring 116, and between the carrier ring 116 and the carrierring shaft 104. This adjustment of weight or density may be accomplishedby any combination of the following means: selection of materials ofdiffering densities or composite combination of materials whichcombination achieves differing densities, and/or void spaces in thevanes.

The pulsatile spherical blood pumping system can be configured to flowtwo different fluids, such as for example oxygen-rich blood andoxygen-poor blood through the same pump as can pump one fluid. FIGS.20A-20E show sequenced views of the pump 10 in operation with thecontrol lever 120 in the 0 degree position as the input shaft 32 isrotated through 180 degrees of revolution and while simultaneouslyflowing two fluids through its interior. In this configuration, thesingle pump 10 acts as two pumps simultaneously, and therefore is ableto do the work of two pumps while occupying much less space than twopumps. For conceptual convenience, the majority of the lower housinghalf 14 is not shown. As discussed with FIGS. 10A-10E, motion of theinput shaft 32 causes each secondary vane 98A, 98B to reciprocate ormove back and forth between a fully open position and a fully closedposition with respect to primary vanes 50A, 50B. Chamber 301 is definedas the space between primary vane 50B and secondary vane 98B, chamber302 is defined as the space between primary vane 50B and secondary vane98A, chamber 303 is defined as the space between primary vane 50A andsecondary vane 98A and chamber 304 is defined as the space betweenprimary vane 50A and secondary vane 98B.

In the depicted embodiment, simultaneous flow of two fluids isaccomplished by connecting upper port 24 to a first fluid source andlower port 26 to a second fluid source. Lower port 24 acts as an outletfor the first fluid and upper port 26 acts as an outlet for the secondfluid. FIG. 20F shows that concept by showing the port openings only.First fluid 196 enters upper port opening 24 and exits lower portopening 24. Second fluid 196 enters lower port opening 26 and exitsupper port opening 26. In the sequences shown in FIGS. 20A-20E, thefirst fluid flows from the first fluid source through upper port 24 intochamber 301, and from chamber 302 out of lower port 24. Simultaneously,the second fluid flows from the second fluid source through lower port26 into chamber 303, and from chamber 304 out of upper port 26. Thisseparation of flows of the two fluids is facilitated by the previouslydiscussed seals between the vanes and the interior of the housing 12,between the vanes and the exterior of the central ball 115, and betweenthe primary vanes 50A, 50B and secondary vanes 98A, 98B.

In similar manner as described for FIGS. 20A-20E, as the input shaft 32is rotated through another 180 degrees of rotation, first fluid flowsfrom the first fluid source through upper port 24 into chamber 302, andfrom chamber 301 out of lower port 24. Simultaneously, the second fluidflows from the second fluid source through lower port 26 into chamber304, and from chamber 303 out of upper port 26. In the depictedembodiment, chambers 301 and 302 transfer only the first fluid throughupper and lower ports 24, and chambers 303 and 304 transfer only thesecond fluid through upper and lower ports 26.

As an example of an embodiment that is particularly useful, as analternative to using a motor to drive pump 10, motive power for rotatinginput shaft 32 of pump 10 may be provided by flowing a first fluid underpressure from a first fluid source in the above configuration throughupper port 24, which alternatingly powers the expansion of chambers 301and 302 which in turn rotates primary vane 50 about input shaft 32.Chambers 303 and 304 then draw in and expel blood fluid from and to therecipient. Advantages of this embodiment include reduced space andelimination of heat that would otherwise be generated by an electricdrive motor. This first fluid is preferably a biocompatible liquid, butmay also include inert and/or humidified gas.

The ability to separately control the flow of two different blood fluidstreams in the same pulsatile blood pumping systems is an importantconcept of the instant invention. In another embodiment of the instantinvention, FIGS. 23A-23E show sequenced views of the pump 10 inoperation with the control lever 120 in the 0 degree position as theinput shaft 32 is rotated through 180 degrees of revolution and whilesimultaneously flowing two fluid streams at two different flow ratesthrough its interior. For conceptual convenience, the majority of thelower housing half is not shown. As discussed with FIGS. 20A-20E, motionof the input shaft 32 causes each secondary vane 98A, 98B to reciprocateor move back and forth between a fully open position and a fully closedposition with respect to primary vanes 50A, 50B, varying the volumes ofchambers 301-304 as previously defined. Simultaneous flow of multiplefluid streams at different flow rates is accomplished by rotating ports26 about the axis of input shaft 32 in relationship to ports 24. In thedepicted embodiment, ports 26 are rotated 20 degrees about the axis ofinput shaft 32. Upper port 24 is connected to a first fluid source andlower port 26 to a second fluid source. Lower port 24 acts as an outletfor the first fluid and upper port 26 acts as an outlet for the secondfluid. In this embodiment, the first and second fluid may be either thesame fluid or different fluids. In the sequences shown in FIGS. 23A-23E,the net flow rate of second fluid from the second fluid source throughlower port 26 has been decreased, due to the altering of the position ofports 26 with respect to the opening and closing of the secondary vanes98A, 98B with respect to primary vanes 50A, 50B, in a manner similar tothat previously described when second shaft assembly 100 is rotated tovarious fixed positions as described for the sequences in FIGS. 10A-10E,12A-12E, 14A-14E.

In this embodiment, rotating the position of ports 26 about the axis ofthe input shaft 32 in relationship to ports 24 may be accomplishedthrough several means. One such means would be to provide eccentric portinserts 27A as shown in FIG. 24. Both upper and lower ports 26 arerotated in this manner to a similar extent, to avoid fluid locking ofthe pump. The shapes provided for the openings of port inserts 27A couldobviously be selected from a great variety (e.g., oblong) to effectvarious alterations of flow through said port openings. This insertmeans may also be alternatively employed with the carrier ring on theoutside of the housing interior, as taught by Stecklein in U.S. Pat. No.5,199,864. As shown in FIG. 25, another such means is to divide housinghalves 14, 16 into quarter sections 14A, 14B, 16A, 16B along the planeperpendicular to the axis of input shaft 32 and intersecting the centerof center ball 115. Flanges are provided to each quarter section toallow sealing of quarter sections 14A, 16A to quarter sections 14B, 16Bafter rotation of ports 24 to a new fixed position (for example, byrotating quarter sections 14B, 16B about the axis of input shaft 32).Additional means of rotating ports 24 about the axis of input shaft 32relative to ports 26 may also be employed, as readily apparent to thoseskilled in the art. This embodiment may be implemented independent of orin combination with any number of the above-mentioned embodiments thatprovide for flow of multiple fluids, that provide for removal of heatfrom the interior of the pump, that provide for changeable ports, orthat provide for stabilization of the structure.

Additional embodiments that independently vary the relative flow ratesthrough at least two ports are possible. These include altering theshape or one or more face angles of any of the vanes 50A, 50B, 98A, 98B,which shape altering may optionally be accomplished by plates driven byhydraulic bladders, providing corresponding adjustments to the flow offluid(s) through chambers 301-304. Another embodiment includes providinga path for relative one-way flow between chambers. The flow path may bethrough or around a vane, and is tapered or valved to preferentiallyallow flow in one direction.

Traditional centrifugal or axial flow pumps used in blood pumpingapplications are moving blood fluids vigorously through the pump duringthe entire cycle of pumping. In the pump described and claimed in theinstant invention blood fluids are drawn into one of the fluid chambersthrough an intake port and held temporarily until the fluid chamberapproaches a discharge port where the blood fluid is discharged as thechamber closes. In this manner the pulsatile blood pumping systemdescribed more closely resembles the action of a human heart, whichbrings in blood and temporarily holds it before discharging.

Having thus described the present invention by reference to certain ofits preferred embodiments, it is noted that the embodiments disclosedare illustrative rather than limiting in nature and that a wide range ofvariations, modifications, changes, and substitutions are contemplatedin the foregoing disclosure and, in some instances, some features of thepresent invention may be employed without a corresponding use of theother features. Many such variations and modifications may be consideredobvious and desirable by those skilled in the art based upon a review ofthe foregoing description of preferred embodiments. Accordingly, it isappropriate that the appended claims be construed broadly and in amanner consistent with the scope of the invention.

1. A pulsatile blood pumping system comprising: a housing having a walldefining a generally spherical interior, said housing having at leastone intake port opening in communication with said interior of saidhousing and at least one discharge port opening in communication withsaid interior of said housing, comprising: a first shaft mounted forrotation relative to said housing about a primary axis; at least oneprimary vane disposed within said interior of said housing that rotatesabout said primary axis of said first shaft; at least one secondary vanedisposed within the interior of said housing and mounted to said primaryvane on a first pivotal axis, said secondary vane pivotally oscillatingbetween alternating relatively open and closed positions with respect tosaid primary vane and defining at least a chamber within said housinginterior having a volume which varies as said primary vane is rotatedabout said primary axis; wherein said at least one intake port openingand said at least one discharge port opening are connected to circulateat least one blood fluid through a living organism.
 2. The pulsatileblood pumping system of claim 1 wherein materials of construction forsaid pulsatile blood pumping system are selected from the groupconsisting of Teflon, titanium, pyrolytic carbon, Dacron, heparin, andpolyurethane.
 3. The pulsatile blood pumping system of claim 1 whereinsaid secondary vane is pivotally coupled to a carrier ring, so that saidsecondary vane is pivotal about a second pivotal axis perpendicular tothe axis of rotation of said carrier ring causing said secondary vane toreciprocate between relatively open and closed positions as saidsecondary vane is rotated about said primary axis by said first shaft;the axis of rotation of said carrier ring being oriented at an obliqueangle in relation to said primary axis of said first shaft.
 4. Thepulsatile blood pumping system of claim 3 further comprising a secondshaft that extends into said interior of said housing opposite saidfirst shaft, said second shaft having a spherical portion about whichsaid primary vane rotates and wherein said carrier ring is rotatablycarried on said spherical portion of said second shaft.
 5. The pulsatileblood pumping system of claim 4 wherein said first shaft is rotatablycoupled to said spherical portion of said second shaft to providerigidity to the structure.
 6. The pulsatile blood pumping system ofclaim 5, wherein said rotatable coupling is accomplished by an extensionof a portion of said first shaft into said spherical portion of saidsecond shaft.
 7. The pulsatile blood pumping system of claim 5 whereinsaid rotatable coupling is accomplished by an extension of a portion ofsaid spherical portion of said second shaft into said first shaft. 8.The pulsatile blood pumping system of claim 5; wherein a fluid channelis provided through the center of said first shaft, into said sphericalportion of said second shaft, and out said second shaft, providing for aflow of lubricant and/or coolant through the interior members of saidpulsatile blood pumping system.
 9. The pulsatile blood pumping system ofclaim 4 wherein seals are installed on both primary and secondary vanesto contact said housing during operation and wherein seals are installedon both primary and secondary vanes to contact said spherical portion ofsaid second shaft during operation.
 10. The pulsatile blood pumpingsystem of claim 4 wherein said second shaft is adjustably mounted tosaid housing so that said second shaft can be oriented in various fixedpositions, and further comprising; an adjustable vane guide bearingmember disposed within said housing, wherein the adjustable vane guidebearing member oscillates said secondary vane between relatively openand closed positions relative to said primary vane in response torotation of said primary vane, varying the point during rotation of saidfirst shaft and said primary vane at which said secondary vane reachesthe relatively open and closed positions relative to said housing andsaid port opening so that communication of said port opening with saidchamber is adjusted and therefore the fluid flow volume and/or directionis adjusted.
 11. The pulsatile blood pumping system of claim 3 whereinsaid carrier ring is an exterior ring mounted in said wall of saidhousing.
 12. The pulsatile blood pumping system of claim 1 wherein aflow pulse profile created by said pulsatile blood pumping system isadjusted through the use of a flow element that is resistive and/orcapacitive in nature, said flow element being in communication with saidpulsatile blood pumping system.
 13. The pulsatile blood pumping systemof claim 1 wherein the flow rate through said at least one dischargeport opening of said pulsatile blood pumping system is adjusted based onfeedback from sensors in said living organism.
 14. The pulsatile bloodpumping system of claim 13 wherein said sensor senses flow pulsations ofat least one of the heart ventricles of said living organism and adjustssaid rotational speed of said first shaft to coincide pulsatile flow ofsaid pulsatile blood pumping system with said flow pulsations of saidheart ventricle.
 15. The pulsatile blood pumping system of claim 13wherein said sensor senses flow demand of at least one of the heartventricles of said living organism and adjusts said rotational speed ofsaid first shaft to match said flow demand.
 16. The pulsatile bloodpumping system of claim 1 wherein said pulsatile blood pumping system isimplanted into the body of said living organism.
 17. The pulsatile bloodpumping system of claim 16 wherein said pulsatile blood pumping systemis attached to the bones, muscles, sinews and/or internal organs of saidliving organism.
 18. The pulsatile blood pumping system of claim 16wherein the exposed surfaces in said pulsatile blood pumping system areporous to promote ingrowth of host cells to further anchor and providebiocompatibility within said living organism.
 19. The pulsatile bloodpumping system of claim 16 wherein a motor to rotate said first shaft isconnected directly to said first shaft and fixedly mounted to saidhousing.
 20. The pulsatile blood pumping system of claim 16 wherein adetached motor to rotate said first shaft is mechanically and/orelectromagnetically linked to said first shaft.
 21. The pulsatile bloodpumping system of claim 16 wherein the power to rotate said first shaftis supplied transcutaneously.
 22. The pulsatile blood pumping system ofclaim 20 wherein power to rotate said first shaft is transmitted viamagnets coupled across skin surface.
 23. The pulsatile blood pumpingsystem of claim 20 wherein said pulsatile blood pumping system isimplanted in chest cavity of living organism and said detached motor isimplanted in abdominal cavity.
 24. The pulsatile blood pumping system ofclaim 1 wherein said pulsatile blood pumping system is located outsidethe body of said living organism.
 25. The pulsatile blood pumping systemof claim 24 wherein a motor to rotate said first shaft is connecteddirectly to said first shaft and fixedly mounted to said housing. 26.The pulsatile blood pumping system of claim 24 wherein a motor to rotatesaid first shaft is mechanically and/or electromagnetically linked tosaid first shaft, but physically detached from said housing.
 27. Thepulsatile blood pumping system of claim 24 wherein said at least oneintake port opening and said at least one discharge port openings areaccomplished by changeable port inserts.
 28. The pulsatile blood pumpingsystem of claim 27 wherein said changeable port inserts are eccentric inshape.
 29. The pulsatile blood pumping system of claim 1 wherein atleast one blood-contacting surface of said pulsatile blood pumpingsystem is selected from the group consisting of heparin, acetylsalicylicacid and derivatives of any of the foregoing.
 30. The pulsatile bloodpumping system of claim 1 wherein at least one additive to blood flowingthrough said pulsatile blood pumping system is selected from the groupconsisting of heparin, acetylsalicylic acid and derivatives of any ofthe foregoing.
 31. The pulsatile blood pumping system of claim 4 whereina fluid channel is provided through the center of said first shaft, intosaid spherical portion of said second shaft, and out said second shaftor out said first shaft, providing for a flow of a flushing mediumthrough the interior members of said pulsatile blood pumping system. 32.The pulsatile blood pumping system of claim 1 wherein seals are providedbetween relatively moving surfaces in said pulsatile blood pumpingsystem to limit the flow of said blood fluid between said relativelymoving surfaces.
 33. The pulsatile blood pumping system of claim 1wherein said primary vanes and/or secondary vanes include magneticportions that are acted upon by electromagnetic fields that aregenerated from within said housing wall or from outside of said housingwall, wherein said action causes said rotation of said primary vane andcauses said oscillation of said secondary vanes.
 34. The pulsatile bloodpumping system of claim 11 wherein said external carrier ring includesmagnetic portions that are acted upon by electromagnetic fields that aregenerated from within said housing wall or from outside of said housingwall, wherein said action causes said rotation of said primary vane andsaid oscillation of said secondary vanes.